Deep breath....
This is Air India we're talking about. Red tape central. Nobody breathes without being told to do so by their superior.
Here's my take. Aircraft diverts to Gatwick - these things happen. They've got passengers at Heathrow wanting to board as well as the passengers on board wanting to get off. Crew has enough hours to go for a quick refuel and hop over to Heathrow provided everything goes to plan. So they park off terminal. Will someone authorise fuel? The crew can't authorise and the request works its' way slowly through the red tape. By the time it's authorised the crew are out of hours. Where's a replacement? Probably in London. Can we call them? More red tape. Yes we can. OK get them to Gatwick. Find the plane. File a flight plan - no slot until....
In the meantime, apart from the fact that they've asked for fuel the guys on board know nothing. No feedback. So they say nothing; they don't want to promise something they can't provide (and get into trouble for doing so). Did the crew ask for food? I doubt it because they would be seen as causing even more problems, in any case "we're getting fuel soon".
I hate to see a great airline bought down in this way. It didn't used to be like this.
I wonder what they'll do when they have a plane stuck at JFK in a snow storm given US law?!
Will it happen again? I hate to say it but probably.